190 AXEL A. OLSSON 



Cardita (Carditamera) affinis Sowerby, Hertlein and Strong, 1946, Zoologica, vol. 31, 



pt. 3, No. 8, pp. 107, 1C8. 

 Glans affinis californica Sowerby, Maxwell Smith, 1944, Panamic Marine Shells, p. 



56, fig. 704. 



Shell elongate, rectangular, often large (length to 70 mm.), with the 

 umbones and beaks placed between the anterior one-fourth and one-fifth, 

 the anterior side, therefore, much shorter and narrower than the posterior. 

 Dorsal and ventral margins long and fairly straight, subparallel, the anterior 

 margin rounded, the posterior wider and subtruncate. The posterior um- 

 bonal slope is high and angular and usually more heavily sculptured. Sculp- 

 ture formed by ribs, usually numbering about 17; of these, the six pos- 

 terior ones and along the umbonal slope are large and usually coarsely 

 scabrous, the others placed more anteriorly small and sometimes so low or 

 flattened as to form smooth, colored radial rays. Hinge variable, the teeth 

 sometimes much distorted and partly obsolete but when fully developed in 

 the following form; the left valve has a large, anterior cardinal tooth 

 bordered on each side by deep sockets while the posterior cardinal tooth 

 is a slender, narrow lamina separated from the nymph by a groove; the 

 right valve has a large, slender cardinal tooth bordered in front by a deep 

 socket; the left anterior tooth is small and placed close to the main cardinal. 

 Outside color usually brown over the posterior side, lighter to almost white 

 on the anterior side. 



Length 68.4, height 26.5 mm., diameter 13.8 mm. Manta, Ecuador. 



This is a common species varying much in size, shape and sculpture, 

 due in part to its habit of living in close quarters as under stones and along 

 narrow crevices. 



Range — Gulf of California southward to northern Peru. Numerous 

 stations cited by Hertlein and Strong in Costa Rica, Nicaragua, Guatemala, 

 and Mexico. Panama: Bucaro. Ecuador: Puerto Callo; Manta; Santa Elena. 

 Peru: Tumbez; Zorritos; Caleta Sal; Mancora. 



Family CONDYLOCARDIIDAE 



Shell small to minute, ovate, suborbicular, subtrigonal to cordate, often 

 resembling an immature Cardita with plain umbones or the beaks may be 

 capped with an exaggerated prodissoconchal cup edged by an upturned or 

 raised rim. Surface smooth or sculptured with strong, radial riblets, and 

 concentric lines. Ligament weak, mostly internal. Hinge of variable develop- 

 ment, the cardinal and lateral teeth commonly merged. 



This is a family of small to minute shells, some species of which 

 (Carditella) resemble immature specimens of Cardita and, therefore, easily 

 overlooked. In Condylocardia, the beaks are capped by an enlarged prodis- 

 soconch surrounded by a raised rim. 



Genus CONDYLOCARDIA (Munier-Chalmas), Bernard, 1896 

 Type species by original designation, C. patdiana (Munier-Chalmas), 

 Bernard. 



Shell small, generally globose, glassy, equivalve, and strongly inequi- 

 lateral, the anterior side longer. The umbones full and capped by a 



